Factors which influence the accuracy of acoustic radiation force impulse (ARFI) elastography for the diagnosis of liver fibrosis in patients with chronic hepatitis C.

Our study tried to identify the factors associated with discordance between liver stiffness values assessed by acoustic radiation force impulse (ARFI) elastography and histologic fibrosis in 106 chronic hepatitis C patients. Liver biopsy (LB) and ARFI measurements were performed in the same session. A discordance of at least two stages of fibrosis in the Metavir scoring system between ARFI results and LB was defined as significant. The performance of ARFI elastography was assessed using the following cut-offs: F1-1.19 m/s, F2-1.34 m/s, F3-1.55 m/s and F4-1.80 m/s. Discordance of at least two stages of fibrosis between ARFI results and histologic assessment were observed in 31.7% of the patients. In an univariate analysis, female sex (p = 0.004), interquartile range interval (IQR) ≥30% (p = 0.04), high alanine aminotransferases (p = 0.008) and high aspartate aminotransferases levels (p = 0.003) were associated with discordances. In a multivariate analysis, the female sex (p = 0.006) and IQR ≥30% (p = 0.004) were associated with discordances. Therefore, IQR parameter should be used for ARFI measurements.